1. Field of the Invention
This invention relates to metal halogen electrochemical cells, especially batteries, and more particularly to metal halogen cells which employ microporous separators to define anolyte and catholyte compartments within the cell.
2. The Prior Art
The art is replete with examples of electrochemical cells employing separators to divide the cells into anolyte and catholyte compartments. Mention of a few representative examples of such art is set forth below.
U.S. Pat. No. 3,773,560 discloses use of a membrane or diaphragm separator to divide a zinc chloride electrochemical cell into two zones or compartments.
U.S. Pat. No. 4,049,886 dicloses a zinc-bromine or zinc-iodine electrochemical cell which employs a microporous separator and to divide the cell into anolyte and catholyte compartments.
U.S. Pat. No. 4,105,829 discloses a metal bromine cell, especially a zinc bromine cell, which employs a bromine complexing agent in the electrolyte and which forms a water immiscible liquid with cathodic bromine. Also disclosed is the use of a separator to divide the cell into an anolyte and catholyte compartment.
Among other things, the separator in such cells serves to prevent contact of the metal anode with the counterelectrode. It also helps reduce contact of the metal anode with cathodic halogen during charging of the cell which, of course, results in auto discharge of the cell.